Add slang shader for ray tracing basic sample

Author: SaschaWillems

.gitignore

@@ -240,4 +240,6 @@ android/.idea/**
 
 libs/vulkan/*.so
 
-.vscode/*
+.vscode/*
+
+__pycache__**

shaders/slang/_rename.py

@@ -0,0 +1,17 @@
+# Copyright (C) 2025 by Sascha Willems - www.saschawillems.de
+# This code is licensed under the MIT license (MIT) (http://opensource.org/licenses/MIT)
+
+from shutil import move
+
+# To match required file names to fother shading languages that don't support multiple entry points, shader files may need to be renamed for some samples
+def checkRenameFiles(samplename):
+    mappings = {}
+    match samplename:
+        case "raytracingbasic":
+            mappings = {
+                "raytracingbasic.rchit.spv": "closesthit.rchit.spv",
+                "raytracingbasic.rmiss.spv": "miss.rmiss.spv",
+                "raytracingbasic.rgen.spv": "raygen.rgen.spv",
+            }
+    for x, y in mappings.items():
+        move(samplename + "\\" + x, samplename + "\\" + y)

shaders/slang/compileshaders.py

@@ -6,6 +6,7 @@
 import os
 import subprocess
 import sys
+from _rename import *
 
 parser = argparse.ArgumentParser(description='Compile all slang shaders')
 parser.add_argument('--slangc', type=str, help='path to slangc executable')
@@ -70,13 +71,15 @@ def getShaderStages(filename):
 dir_path = dir_path.replace('\\', '/')
 for root, dirs, files in os.walk(dir_path):
     for file in files:
-        if (compile_single_sample != "" and os.path.basename(root) != compile_single_sample):
+        folder_name = os.path.basename(root)
+        if (compile_single_sample != "" and folder_name != compile_single_sample):
             continue
         if file.endswith(".slang"):
             input_file = os.path.join(root, file)
             # Slang can store multiple shader stages in a single file, we need to split into separate SPIR-V files for the sample framework
             stages = getShaderStages(input_file)
             print("Compiling %s" % input_file)
+            output_base_file_name = input_file
             for stage in stages:
                 if (len(stages) > 1):
                     entry_point = stage + "Main"
@@ -102,8 +105,9 @@ def getShaderStages(filename):
                         output_ext = ".mesh"
                     case "amplification":
                         output_ext = ".task"
-                output_file = input_file + output_ext + ".spv"
+                output_file = output_base_file_name + output_ext + ".spv"
                 output_file = output_file.replace(".slang", "")
                 res = subprocess.call("%s %s -profile spirv_1_4 -matrix-layout-column-major -target spirv -o %s -entry %s -stage %s -warnings-disable 39001" % (compiler_path, input_file, output_file, entry_point, stage), shell=True)
                 if res != 0:
-                    sys.exit(res)
+                    sys.exit(res)
+    checkRenameFiles(folder_name)

shaders/slang/raytracingbasic/raytracingbasic.slang

@@ -0,0 +1,60 @@
+/* Copyright (c) 2025, Sascha Willems
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ */
+
+RaytracingAccelerationStructure accelStruct;
+RWTexture2D<float4> image;
+struct CameraProperties
+{
+	float4x4 viewInverse;
+	float4x4 projInverse;
+};
+ConstantBuffer<CameraProperties> cam;
+
+struct Attributes
+{
+    float2 bary;
+};
+
+struct Payload
+{
+	float3 hitValue;
+};
+
+[shader("raygeneration")]
+void raygenerationMain()
+{
+	uint3 LaunchID = DispatchRaysIndex();
+	uint3 LaunchSize = DispatchRaysDimensions();
+
+	const float2 pixelCenter = float2(LaunchID.xy) + float2(0.5, 0.5);
+	const float2 inUV = pixelCenter/float2(LaunchSize.xy);
+	float2 d = inUV * 2.0 - 1.0;
+	float4 target = mul(cam.projInverse, float4(d.x, d.y, 1, 1));
+
+	RayDesc rayDesc;
+	rayDesc.Origin = mul(cam.viewInverse, float4(0,0,0,1)).xyz;
+	rayDesc.Direction = mul(cam.viewInverse, float4(normalize(target.xyz), 0)).xyz;
+	rayDesc.TMin = 0.001;
+	rayDesc.TMax = 10000.0;
+
+    Payload payload;
+    TraceRay(accelStruct, RAY_FLAG_FORCE_OPAQUE, 0xff, 0, 0, 0, rayDesc, payload);
+
+	image[int2(LaunchID.xy)] = float4(payload.hitValue, 0.0);
+}
+
+[shader("closesthit")]
+void closesthitMain(inout Payload p, in Attributes attribs)
+{
+    const float3 barycentricCoords = float3(1.0f - attribs.bary.x - attribs.bary.y, attribs.bary.x, attribs.bary.y);
+    p.hitValue = barycentricCoords;
+}
+
+[shader("miss")]
+void missMain(inout Payload p)
+{
+    p.hitValue = float3(0.0, 0.0, 0.2);
+}